Heel engaging unit for a safety ski binding



March 11, i969 w, SUHNER 3,432,180

HEEL ENGAGING UNIT FOR A SAFETY SKI BINDING Original Filed Nov. 8, 1966Sheet of 5 INVENTOR. bg {t} fuer' W. SUHNER HEEL ENGAGING UNIT FOR ASAFETY SKI BINDING Sheet Original Filed Nov. 8, 1966 INVENTOR.

(u A u W. SUHNER March ll, 1969 3,432,180 HEEL ENGAGING UNIT FOR ASAFETY. sx1 BINDING Sheet Original Filed Nov. 8, 1966 INVENTOR. 4/,2 r 7fu er March 11, 1969 w. SUHNER 3,432,180 HEEL ENGAGING UNIT FOR `ASAFETY SKI BINDING Original Filed Nov. 8, 1966 Sheet 4 of INVENTOR.

March 11, 1969 w. SUHNER 3,432,180

HEEL ENGAGING UNIT FOR A SAFETY sx1 BINDING Original Filed Nov. 8, 1966Sheet 5 of 5 United States Patent Office Claims priority, applicationSwitzerland, Nov. 11, 1965, 15,587/ 65 U.S. Cl. 28011.3S 31 Claims Int.Cl. A63c 9/00 ABSTRACT OF THE DISCLOSURE The present invention relatesto a heel engaging unit for a safety ski binding, and more specificallyto a strapless heel engaging unit provided with heel engaging meanswhich automatically secure the heel of a ski boot to the unit Iwhen theuser steps with the heel into the heel engaging means while the latterare in a step-in position and which subsequently holds the ski engagingmeans in a downhill run position in which the bottom surface of the heelwill be maintained closely adjacent to the top surface of the ski or ina walking or cross-country skiing position in which the heel of the skiboot may move within Certin limits upwardly and downwardly with respectto the top surface of the ski.

This is a continuation of application Ser. No. 592,866, filed Nov. 8,1966.

Heel engaging units for safety ski bindings are known in the art inwhich the heel engaging unit cooperates with a front engaging unit forautomatically securing the heel engaging unit to the heel of a ski bootwhen the user steps with the ski boot into the binding, however theseknown safety ski bindings have the disadvantage that they are adaptedonly for use during downhill run since in these bindings the heel of theski boot cannot be lifted from the top surface of the ski.

Other strapless Iski bindings are known in the art which are suitablefor downhill run as well as for cross-country skiing, These ski bindingsare usually provided for crosscountry skiing with additional members,for instance a plate extending beneath the sole of the ski boot. Suchplates are liable to twist or break, and in addition these ski bindingsuse for cross-country skiing mechanical linkage systems which have to beclosed by means yof a tightening member. The changeover of these knownski bindings for downhill run use or for cross-country skiing use isusually diicult and time-consuming, and these known ski bindings arealso very often dependent on a specific shape of the heel of the skiboot for their proper function. ln addition these known ski bindingshave usually a poorly functioning release mechanism for releasing theheel engaging means from the heel of a `ski boot during a fall of theskier to thus prevent injury to the skier during such fall.

It is an object of the present invention to provide a heel engaging unitfor a safety lski binding which avoids the above-mentioned disadvantagesof such units known in the art.

It is a further object of the present invention to provide a heelengaging unit for a safety ski binding suitable for downhill run use aswell as for cross-country skiing which not only permits a faultless andquick engagement and disengagement with the heel of a ski boot, butwhich will also permit, even during skiing, a quick change-over from oneto the other use.

It is also an object of the present invention to provide a heel engagingunit for a safety ski binding of the aforementioned kind which not onlypermits a perfect guiding of the ski during cross-country skiing, butwhich also per- Patented Mar. 11, 1969 mits to limit the up-and-downmovement of the heel of the ski -boot relative to the ski duringcross-country skiing so that the user will tire less than with other skibindings known in the art.

It is an additional object of the present invention to provide a heelengaging unit for a safety ski binding with exactly adjustable means forinstantaneously releasing the heel engaging means of the unit from theheel of the ski boot during excessive upward pressure on the heelengaging means, as will occur during a forward fall of the skier.

The heel engaging unit according to the present invention is straplessand does not require any connecting elements which protrude laterallyto` opposite sides of the ski boot or which are arranged beneath thesole of the ski boot. It is further adapted for use with most of the skiboots presently available without requiring any additional elements ormetal fittings mounted on the ski boot. The heel engaging Iunit is alsousable in combination with Various front units or front jaws presentlyavailable on the market. The pressure at which the front portion of aski boot is pressed against the front jaws by the heel engaging unit ofthe present invention is steplessly adjustable and so is the releasingmoment for releasing the heel engaging means of the heel engaging Iunitfrom the heel of a ski boot during forward fall. of the skier. Theaforementioned pressures are readable on the heel engaging unit afterthe skier has stepped into the safety ski binding and the means forindicating the pressure will not indicate the adjusted pressure but theactually acting pressure.

With the above objects in View, the heel engaging unit according to thepresent invention adapted to cooperate with a front unit of a safety skibinding for pressing the front portion of a ski boot into said frontunit of the ski binding mainly comprises support means adapted to bemounted on a ski rearwardly of the front unit thereon, heel engagingmeans constructed and arranged to automatically egage the heel of a skiboot when the user steps with the heel onto the heel engaging means, andlinkage means connecting the heel engaging means to the support meansand guiding the heel engaging means movable relative to the ski along apredetermined portion of a substantially circular path having itsturning axis in the region of the top surface of the ski and adjacentthe front unit of the ski binding so that during the use of the skibinding for walking the heel engaging means remain substantiallynon-shiftably connected to the heel of the ski boot.

The linkage means preferably comprise a first parallelogram guideincluding an elongated member having a front portion and a rear portionand a pair of first link means respectively pivotally connected atopposite end-s thereof to said support means and the elongated member inthe region of the rear portion of the latter, and a second parallelogramguide including a pair of second link means one of which is pivotallyconnected at one end thereof to one of the first link means and at theother end thereof to the heel engaging means and the other of which ispivotally connected at one end thereof to the elongated member in theregion of the front portion of the latter and at the other end thereofto the heel engaging means.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following `description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a longitudinal section taken along the line I-I of FIG. 5 of aheel engaging unit according to the present invention and `showing thisunit in the uppermost position during use of the unit for walking orcross country skiing;

FIG. 2 is a partially cross sectioned side View of the unit illustratedin FIG. l and showing the unit in a stepin position ready to receive theheel of a ski boot;

FIG. 3 is a sectional view similar to FIG. l and showing the unit indownhill run position;

FIG. 4 is a partially sectioned side view of the unit and showing theunit adjusted for walking on steep slopes whereby the position shown infull lines is the lowest and the position shown in dash-dotted lines thehighest of the thus adjusted positions;

FIG. 5 is a top View of the unit shown in the position as in FIG. 3;

FIGS. 68 illustrate certain components of the unit respectively in sideview, front view and section; and

FIGS. 9-12 illustrate some alternatives of parts of the unit.

Referring now to the drawings and more specically to FIG. 1 of the same,it will be seen that the heel engaging unit according to the presentinvention for a strapless safety ski binding mainly comprises supportmeans which include a base plate 1 adapted to be connected by screws orthe like to the top surface of a ski 2, as indicated in FIG. 3, and aframe 3 mounted on the base plate 1 movable in longitudinal direction ofthe ski. The frame 3 includes a pair of guide rails 5 which respectivelyencompass lateral edge portions of the base plate 1 to guide the framein longitudinal direction of the base plate, and a pair of lateral walls7 projecting upwardly from the guide rails 5 and being connected at thefront end the rear end thereof by a pair of transverse bolts 11 and 13,respectively. The bolts 11 and 13 are formed with bores therethroughaligned along a common axis normal to the axis of the bolts and a rod 15extends through the aforementioned bores preferably fixed to the bolts11 and 13 in any convenient manner. A cylindrical member 17 provided onthe outer surface thereof with a screw thread engaging in correspondingthreads 27 on the Ibase plate 1 is mounted on the rod 15 coaxiallytherewith and tunably and axially movable with respect thereto. A pairof coil compression springs 19 and 21 are arranged to the left side, asviewed in FIG. l, of the member 17 about the rod 15. An indicator member23 is slidably arranged on the rod 15 between the left end face, asviewed in FIG. 1, of the member 17 and the right end of the spring 21,and the indicating member 23 extends with at least one lateral portionthrough a cutout 9 in at least one of the side walls 7 of the frame 3.The indicating member 23 cooperates with marks 25 provided on the guiderails 5. An abutment member 29 is located between opposed ends of thesprings 19 and 21 and guided on the rod 15 by means of a sleeve 30fixedly connected to or integral with the member 29.

The heel engaging unit comprises further heel engaging means includingthe members 92, 107 and 134 constructed and arranged, as will bedescribed later on in detail, to automatically engage the heel of a skiboot when the user of the ski steps with the bottom face of the heelonto a forwardly projecting engaging portion 110 on the member 107.

The heel engaging unit includes further linkage means connecting theheel engaging means to the frame 3 of the support means for guiding theheel engaging -means relative to the ski along a predetermined portionof a substantially circular path having its turning axis in the regionof the top surface of the ski and adjacent to a front unit providedthereon so that during use of the ski binding for walking the heelengaging means remains substantially non-shiftably connected to the heelof the ski boot.

The linkage means comprise a rst parallelogram guide including a pair ofrst link means or link arms 35 and 37. The longer arm 3S is pivotallyconnected at its bottom end to a bearing bolt 31 extending between afront portion of the side walls 7, whereas the lower end of the shorterarm 37 is pivotally connected to a bearing bolt 33 extending between arear portion of the aforementioned side walls. The first parallelogramguide includes furthe-r an elongated member 39 which is preferablycap-shaped and a pair of upper bearing bolts 43 and 45 extend betweenand are connected to side walls of the cap-shaped member 39 and theupper ends of the link arms 35 and 37 are respectively pivotallyconnected to the bearing bolts 43 and 45. A rubber buffer is preferablyconnected to the rear end of the cap-shaped member 39.

The longer link arm 35 includes an upper and a lower bearing bushing 47,51 respectively mounted on the bearing bolts 43 and 31 and connected toeach other by parallel walls 49 extending spaced from each other andsubstantially normal to the axes of the bushing 47 and S1, as best shownin FIG. 6. The upper bushing 47 is provided substantially midway betweenopposite ends thereof with an annular groove 53, for a purpose as willbe described later on. A cam 55 projects from the lower bushing 51,which cam has a stepped portion 56 and which defines together with theca-m a cam face 58.

The heel engaging unit includes further a second parallelogram guideincluding two pairs of link members 84 and 130. The upper shorter linkmembers 84 are pivotally mounted at the rear ends thereof on a pivot pin41, whereas the lower longer link members 130 are pivotally mounted atthe rear ends thereof by means of a pivot pin 132 on the link member 37between the ends of the latter. The front ends of the link members 84and 130 are pivotally connected to the heel engaging means for movablycarrying the same. As best shown in FIG. 8 each of the link members 84is formed adjacent one end thereof with an opening 89 through which thepivot pin 41 extends, whereas in the region of the opposite end thereofa short cylindrical member or shaft 86 is turnably mounted. The shortshafts `86 of the link members 84 respectively extend through bores inupper portions 94 of the member 92 so that the latter may turn about theaxes 104 of the two short shafts 86. The member 92 has a front wall 96which is provided at its front surface thereof with a plurality of teeth98 and which if formed substantially midway with a longitudinal slot100. The member 92 is further formed in the side walls thereof withmouth-shaped guide slots 102.

A first heel engaging member 134 is adjustably connected to the member92 and for this purpose the heel engaging member 134 is provided at itsrear face teeth 136 corresponding to the teeth 98 and interengaged withthe latter. The heel engaging member 134 is connected by means of ascrew 144 extending through the slot 100 and a nut 145 to the member 92.Preferably the nut 145 has projections extending into the slot 100 toprevent turning of the nut during tightening of the screw 144. The heelengaging member 134 has at its upper end a forwardly projecting heelengaging portion 142 adapted to engage the upper surface of a rimportion of a heel 4 of a ski boot as indicated in FIG. 3. The heelengaging portion 142 has an upper downwardly inclined guide surface 140and this member has also a front guide surface 147 adapted to guide theheel of a ski boot onto a forwardly projecting portion of the secondheel engaging member 1'07.

The second heel engaging member 107 has a bottom wall, the front portion110 of which forms a second heel engaging portion adapted to engage thebottom surface of the heel of a ski boot, as shown in FIG. 3, and a pairof side walls 112, each provided with a pair of bores 114 and 116 asbest shown in FIG. 7. The side walls 112 are extended at the upper endthereof into rearwardly projecting noses 118 each having an upper guidesurface 120 and a bottom edge 122 adapted to engage onto the bolts 41. Abolt 124 extends through the bores 116 in the `side walls of the member107, and the bolt 124 extends also through bores 88 in the short shafts86 carried by the link members 84, which bores 88 are eccentricallyarranged with regard to the axis 104 s of the shafts 86. The bottom wallof the member 107 has a rearwardly projecting locking portion 126. A pin128 extending through the bores 114 in the side walls of the membery1017 pivotally connects the latter to the front ends of the linkmembers 130.

Since ski shoes are manufactured which have so-called walking heels, inwhich the rear end of the sole is rounded and would therefore notproperly engage the portion 110 of the member 107, a bore 110', as shownin FIG. 7 may be provided in which a projecting pin or the like, notshown in the drawings, may be secured.

A lever 60 is pivotally mounted at the front end thereof by means of thebolt 41 on the cap-shaped member 39. The side walls of the lever 60carry in the region of the front end thereof a pair of rollers 74, asbest shown in FIGS. 1 and 5, which are adapted to engage the upper faces120 of the noses 118 on the member 107. The lever 60 carries further aroller 76 turnably mounted thereon by a pin 78. Spring means in form ofa coil spring 71 are operatively con-nected to the lever 60 tending whenstressed to turn the latter depending on the position of the lever incounterclockwise or clockwise direction about the pivot pin 41. The coilspring 71 is guided by means of guides 66, 68 respectively connected atthe upper ends thereof by short stud pins 62, 64, only one of which isactually illustrated in the drawings, to side walls of the lever 60.Sandwiched between these guide members 66 and 68 is an additional guidemember 70 which is connected by means of a fork 72 located in the groove53 of the bushing 47 to the link member 35. The lever 60 has further twodownwardly projecting noses 80, a rearwardly extending handle portion 82and further between the noses 80 and the roller 76 and further twooutwardly extending abutment portions 81.

The above-described heel engaging unit will operate as follows:

In FIG. 2 the unit is illustrated in a step-in position ready to receivea heel of a ski boot. In this position the cap-shaped member 39 is inits lowest position just above the two guide rails 5 and covers theadjusting screw 17 and the coil springs 19 and 21. Only the indicatorslide 23 projects with later-al portions thereof through the cutouts 9of the side walls 7. The lever 60 is in slightly lifted position inwhich the roller 76 carried thereby abuts against the portion 56 of thecam 55 as well as against the rearwardly projecting locking portion 126of the member 107. The two rollers 74 are located beneath the noses 118of the member 107 so that the latter is freely turnable about the bolt128.

The member 92, which is turnable about the short shafts 86 of the links84, is through the guide slots 102 and the bolt 128 in operativeconnection with the member 107. The locking portion 126 of the member107 engages 4the roller 76 in this position at a point which is abovethe Iturning axis of the roller 76. In this position of the unit theheel 4 of a ski boot is pushed against the heel engaging portion 1110 ofthe member 107 by moving the heel along the guide faces 147 of themember 134 and if the heel i-s then pressed downwardly onto the portion110, the members 107 and the links 84 will be turned about the bearingbolt 41 while the guide slots 102 move along the pin 128 downwardly andrearwardly. At the same time the whole movable upper part of the unit ispushed rearwardly whereby the bearing bolts 31, respectively 33 `senveat fixed points, whereas the link members 132 swing downwardly andrearwardly. During this movementof the members 107 and 92 the shortshafts 86 are also turned so that the bolts 124 will move from theposition `shown in FIG. 2 to the position shown in FIG. 3, whereby thespacing between the members 134 and 107 respectively bet'ween the heelengaging portions 142 and `110 of these members will be changedcorresponding to the eccentricity of the axes of the bolts 124 and theshort shafts 86.

In this way a proper securing of the heel between the members 107 and134, which in the step-in position as shown in FIG. 2 are spread apartto facilitate easy insertion of the heel, is assured. The link members84 will turn about the bearing bolt 41 until the heel engaging portion142 of the member 134 will engage the upper rim surface of the heel. lIfthe heel is now further pressed downwardly, then the movable parts ofthe unit are pushed rearwardly since the shoe engages with a frontportion thereof a front unit of the ski binding, no-t shown in thedrawing, Thereby the two springs 19 and 21 are compressed. This pressureacts in longitudinal direction of the shoe sole and will obtain apredetermined value depending on the adjustment of the adjusting screw17. The thus obtained pressure is readable on the lateral marks 25.

During lifting of the ski boot the member 92 has the tendency to turnabout the axis of the short shaft 86 whereby the lower part of themember 134 is pressed against the heel 4 while the upper part tends tomove away from the latter. This ltendency is partly counteracted by thepressure exerted by the springs 19 and 21. This tendency can becompletely eliminated by the following provisions:

(a) The member 92 is guided on the member 107 in such a manner thatthese members are movable relative to each other in direction of a lineconnecting the centers of the bores 114 and 116 in the member -107 orslightly inclined to this line and so that the member 92 may also turnabout the axis of the shafts 86 within narrow limits. This guiding isobtained by means of the guide slots 102 which are cooperating with thebolt 128 xed to the member 107. lThe thus obtained limited turningmovement assures that the ski boo-t in the downhill run position shownin FIG. 3 is not pressed too hard against the top surface of the ski.

(b) Another possible solution consists in providing the member 92 withtwo noses 92 similar to the noses on the member 107, which extend overthe bearing bolt 41 and which during lifting of the heel 4 abut againstthis bolt. The shoe releasing effect occurs in this case only shortlybefore displacement of the roller 76. The force acting thereby on thisroller is, due to the lever action produced by the turnable mounting ofthe member 107 between the member 134 and the mentioned abutment on thebearing bolt 41, greater than th-e force produced during lifting of theheel (FIG. l2).

During movement of the various engaging unit from the position as shownin FIG. 2 to the position as shown in FIG. 3, the locking portion 126will glide downwardly along the surface of the roller 76 and when thelocking portion 126 passes downwardly beyond the critical point (FIG.3), the lever 60 tends under the influence of the spring 71 to turn inclockwise direction so that the roller 76 is moved on the cam surface 58of the cam portion 55 against the point of the cam portion to therebyexert on the members 92, 107 and 134 a closing moment and to hold thesemembers in locked position. Since the locking portion 126 slides on theturnable roller 76, the wear on these two components will be very small.

During downward movement of the heel 4 the springs 19 and 21 will becompressed, since the front portion of the ski boot is held by a frontunit of the ski binding, not shown in the drawing. The forward pressureproduced by the springs 19 and 22 will depend on the adjustment of thescrew member 17 on the base plate 1 and the forward pressure exerted bythe springs is indicated by the indicator slide 23 and the marks 25. Thecompression of the spring 19 can, due to the length of the sleeve 30,not `surpass a predetermined magnitude. The adjusting screw 17 may beadjusted in such a manner that when a desired compression of the springs19 and 21 is obtained in the downhill run position, the lever 60 abutsagainst the cap-shaped member 39 and prevents: that the roller 76 ismoved further forwardly along the locking portion elements of the heel 7126 so that the whole system would be locked and could be opened only-by turning the lever 60 by means of extraneous forces incounterclockwise direction, that is, the heel engaging members would notopen during a forward fall of the skier, and the ski binding would notact as safety ski binding any longer.

In the downhill run position, as shown in FIG. 3, the roller 76 is movedforwardly by the lever 60 until the two noses 80 on the side walls ofthe lever abut with front faces thereof against the abutment member 29which is arranged axially movable between the opposed ends of thesprings 19 and 21.

The compression of the springs 19 and 21 determines therefore theposition of the member 29 and therewith the position of the roller 76with regard to the locking portion 126. The greater the compression ofthe springs 19 and 21 is, the further will the roller 76 move over thelock-ing portion 126 and the greater will be the necessary force to openthe binding during overloads, that is, during a forward fall of theskier. The release moment is therefore dependent on the adjustment ofthe adjusting screw 17 and the thus produced compression of the springs19 and 21. This simplifies proper adjustment of the safety ski binding.

To adjust the moment at which the binding opens during a forward fall ofthe user it is also possible to provide the following means:

The maximum forward movement of the roller 76 over the locking portion126 may be adjusted by providing an adjusting screw 153 as shown indash-dotted lines in FIG. 3 which abuts with its upper end against thebottom surface of the handle portion of the lever 60 to prevent therebyfurther turning of the lever in clockwise direction and resultingforward movement of the roller 76.

Furthermore, the elements cooperating with the spring 71 may be designedin such a manner that the closure pressure acting on the roller 76 andproduced by the spring 71 is provided with a characteristic which isdesirable for the opening of the binding during a fall of the skier.

When during a fall of the skier the roller 76 is pressed upwardly, dueto upward forces exerted on the heel engaging member 134, then thespring 71 will be cornpressed during a first part of this movement. Thecounterpressure of the spring 71 increases therefore. Since, however,the lever 60 is turnable mounted on the bolt 41 and the guide rod 70 ofthe spring 71 is turnably mounted by means of the fork 72 on the bearingsleeve 47 of the link member 35, there will result during turning of thetwo bolts 62 and 46, against which the spring 71 abuts, about thebearing bolt 41, a reduction of the acting lever arm for the force ofthe spring 71, which in the position shown in FIG. 3 tends to turn thelever 60 in clockwise direction about the bearing bolt 41. The systemmay be designed in such a manner that during upward movement of the roll76 the acting lever arm of the spring 71 decreases more than the springpressure increases so that the closing moment decreases with increasingupward movement of the roller to thereby assure a sudden release of theheel during a fall.

In order to bring the heel engaging unit from the downhill run position,as shown in FIG. 3, to a walking or cross-country skiing position, thelever `60 is lifted by hand or by the plate of the ski pole to theposition shown in FIG. l. The roller 76 is thereby disengaged from thelocking portion 126 of the member 107 and the spring 71 is released. Theoutwardly bent portions 81 on the lever 60 will engage with the topportion of the cap-shaped member 39 to limit the turning movement of thelever 60. The two rollers 74 are moved over the noses 181 of the member107 so that the latter may turn about the axis of the bearing `bolt 41and so that the members 92 and 134 are also turned about the bearingbolt 41, while the turning movement is produced by the link members 130.Due to the disengagement of the roller 76 from the locking portion 126,the upper part of the unit may swing about the link arms 35 and 37 sothat the cap-shaped member 39 with the elements connected thereto may beswung upwardly to the position as shown in FIG. l and again downwardlyto the position as shown in FIG. 3. This position of the lever permitstherefore during walking to tilt or roll the sole of the ski boot on thetop surface of the ski 2. Thereby the members 92 and 134 will movesubstantially on a circular arc, the turning axis of which is locatedbetween the front unit of the ski binding and the heel engaging unit,preferably in the region of the toes of the skier, so that the distancebetween the portion of the member 107 and the portion 142 of the member134 will remain substantially constant and so that during this movementthere will practically be no relative movement between the heel and theheel engaging portions which would result in damage to the ski boot.

The members which engage the heel of the ski boot will, due to thecircular movement of the heel engaging means not change the positionrelative to the heel. This result is obtained in the following manner:

During movement of the lever 60 from the position shown in FIG. 3 to theposition shown in FIG. 1, the two rollers 74 which are mounted on thelever are moved over the two noses 118 of the member 107. The noses 118are therefore held onto the bearing bolt 41, which prevents an upwardtilting of the link members 84 since the pin 124, extending through thebores `88 and lixed at the outer ends thereof to the member 107, willprevent such movement. The two noses 11S of the member 107 are formed insuch a manner that during movement of the lever 60 to the position shownin FIG. 1 the bottom edge faces 122 of the noses 118 are tightly pressedagainst the bearing bolt 41 even if such a tight engagement shouldinitially be prevented by snow accumulations or the like.

The above-described substantially circular movement of the heel engagingmeans, that is the members 92, 107 and 134, is obtained in theconstruction shown in the drawing by connecting the mem-ber 107 to theshorter link member 37 by means of the link members 130'.

The substantially circular movement of the heel engaging means can,however, also be obtained in the following manner:

(a) The link members may also be connected at the rear ends thereof tothe longer link member 35 instead to the shorter link member 37 (FIG.9).

(b) Instead of the link members 130, a roller or a slide member may beconnected to the lower portion of the member 107 and this roll or slidemember may be guided along a path which preferably is in the form of anupwardly extending circular .arc 107 (FIG. 10).

(c) The members 130 may be lixedly connected or 'be integrally formedwith the member 107 and provided at the rear ends thereof with slots inwhich rollers or guide members are arranged which are mounted on arearwardly extended portion of the link arm 35 or on an elongatedportion of the link arm 37 (FIG. ll).

During lifting of the lever `60 to the position shown in FIG. 1 the linkmembers 84 are maintained in a stable locking position in which thecommon axis of the short shafts 86 is located below a horizontal line`passing through the axis of the bearing bolt 41, and therefore the heelof the ski boot will not be released during movement of the elements ofthe unit to the position shown in FIG. l. The forces of the heel of theski boot which are transmitted to the link members 84 tend to turn thelatter to an even further stable position.

The longitudinal pressure produced by the compression springs 19 and 21hardly changes due to the substantially circular lifting movement of theheel 4 so that any wear on the rails S will `be relatively small. Bymeans of spacer discs, which may be inserted between the top surface inthe ski and the base plate 1, it is possible to vary the position of thementioned circular movement to obtain, during use of ski boots ofdifferent size, the same relationship 4with regard to the longitudinalpressure produced by the springs 19 and 21.

Since the longitudinal pressure during lifting of the heel remainssubstantially constant, the resistance against lifting of the heel willbe very small, since only frictional forces will have to be overcome.This is especially advantageous during use of the ski binding forcross-country skiing. The change-over from the position shown in FIG. 1for cross-country skiing to the downhill run position shown in FIG. 3 isproduced by downward pressure on the handle portion 82 of the lever 60.

Rubber buffers 40 connected to the inner surface of the cup-shapedmember 39 at the rear end of the latter by bent-over flaps integral withthe member 39 form resilient abutments for the link member 37 duringcrosscountry skiing.

In order to bring the heel engaging unit into the step-in position asshown in FIG. 2, the lever `60 is lifted from the position shown in FIG.3 until the roller 76 abuts against the portion 56 of the cam S5 on thelower bearing bushing 51 of the longer link arm 35, and thereafterpulling on the yoke 138 on the member 92 so that the latter, togetherwith the member 134, is lifted and tilted backwardly to the positionshown in FIG. 2.

By moving the lever `60 to an intermediate position as shown in FIG. 4,the outwardly bent portions or limiting means 81 on the lever 60 willabut against the lower bearing bushing 51 limiting thereby downwardmovement of the heel engaging means so that the latter may not move tothe position shown in FIG. 3, which is especially desirable during useof the ski for upward walking on steep slopes.

The mova-ble upper part of the heel engaging unit can be removed fromthe ski 2 while leaving the base plate 1 connected thereto. In order toremove the upper part of the unit from the ski it is only necessary todisengage the adjusting screw 17 from the base plate by screwing thescrew 17 rearwardly and afterwards the whole upper part of the unit maybe slid rearwardly along the guide rails 5 and removed from the -baseplate 1. If the skier has several pairs of skis, it is only necessary toobtain base plates 1 vfor each pair of -skis and to mount then the upperpart of the unit on the respective base plate. For skis to be rented, itis preferred to obtain longer base plates 1 to provide for a greateradjustability so that the unit may be used for ski boots of differentsize. In the downhill run position the adjusting screw 17 is protectedby the cap-shaped member 39 and an adjustment of the screw 17 ispossible only when the unit is in the walking position. Furthermore, dueto the specific configuration of the lever and the cap-shaped member 39as shown in the drawing, the whole unit has a closed and pleasingappearance. Due to the pressure of the springs 19 and 21, the threads ofthe adjusting screw 17 are in tight frictional engagement with thethreads 27 on the base plate so that an inadvertent turning of theadjusting screw is prevented.

It will 4be understood that each of the elements described above, or twoor more together, may also find a `useful application in other types ofheel engaging units for a safety ski binding differing from the typesdescribed above.

While the invention has been illustrated and described as embodied in aheel engaging unit for a safety ski binding adjustable between adownhill run position and a cross-country skiing position, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

What is claimed as new and desired to tbe secured by Letters Patent is:

1. A heel engaging unit for a safety ski binding adapted to cooperatewith a front unit of the ski binding for pressing a front portion of aski boot into the front unit of the ski binding, said heel engaging unitcomprising support means adapted to be mounted on a ski rearwardly ofthe front unit thereon; heel engaging means constructed and arranged toautomatically engage the heel of a ski boot when the user steps with theheel into said heel engaging means; and linkage means connecting saidheel engaging means to the support means, said linkage means extendingrearwardly of said heel engaging means and guiding said heel engagingmeans movably relative to the ski along a predetermined portion of asubstantially circular path having its turning axis in the region of thetop surface of the ski and adjacent the front unit of the ski binding sothat during use of the ski binding for walking said heel engaging meansremains substantially non-shiftably connected to the heel of the skiboot.

2. A heel engaging unit as defined in claim 1, wherein said linkagemeans comprises a first parallelogram guide including an elongatedmember having a front portion and a rear portion, and a pair of firstlink means respectively pivotally connected at opposite ends thereof tosaid support means and said elongated member in the region of the rearportion of the latter, and a second parallelogram guide including a pairof second link means, one of said second link means being pivotallyconnected at one end thereof to one of said first link means and at theother end thereof to said heel engaging means, and the other of saidsecond link means lbeing pivotally connected at one end thereof to saidelongated member in the region of the front portion of the latter and atthe other end thereof to said heel engaging means.

3. A heel engaging unit as defined in claim 2, wherein said heelengaging means includes a first heel engaging member having a first heelengaging portion adapted to engage an upper face of a rim portion on theheel of the ski boot, a second heel engaging member having a second heelengaging portion adapted 'to be engaged by a bottom face of the heel,said first and second heel engaging members being connected to eachother movable between a step-in position in which said second heelengaging portion projects forwardly beyond said first heel engagingportion, and an engaging position in which said heel engaging portionsare spaced from each other a distance smaller than in said step-inposition, said heel enaging portions being brought to said engagedposition by pressing the bottom face of the heel against the second heelengaging portion.

4. A heel engaging unit as defined in claim 3, and including lockingmeans cooperating with said heel engaging members for locking the Samein said engaged position.

5. A heel engaging unit as defined in claim 4, wherein sald lockingmeans include lever means pivotally mounted on said elongated membermovable between a first position in which said lever means cooperateswith said heel engaging means for maintaining the same in a doWnhill runposition in which said second heel engaging member is maintained closelyadjacent the top surface of the ski, and a walking position in whichsaid heel engaging means may move along said circular path.

6. A heel engaging unit as defined in claim 5, wherein said lever meansinclude a rst engaging portion cooperating with said heel engaging meansin said first position of said lever means for maintaining said heelengaging means in said downhill run position, and a second engagingportion cooperating with said heel engaging means in said secondposition of the lever means for permitting said heel engaging means tomove along said circular path while maintaining said heel engagingmembers in said engaged position.

7. A heel engaging unit as defined in claim 6, wherein said first andsecond engaging portions are constituted by rollers turnably mounted onsaid lever means.

8. A heel engaging unit as defined in claim 3, and including eccentricmeans cooperating with said heel engaging members for moving the samerelative to each other to said engaged position during exertion ofpressure on said second heel engaging portion.

9. A heel engaging unit as defined in claim 8, wherein said eccentricmeans includes a first member turnably about a first axis and engagingone of said heel engaging members, and a second member carried by saidfirst member and having an axis arranged eccentrically with respect tosaid first axis and engaging the other of said heel engaging members,the distance between said axes determining movement of said heelengaging members relative to each other.

10. A heel engaging unit as defined in claim 9, wherein said firstmember of said eccentric means is carried by said other of said secondlink means in the region of the other end thereof and turnably aboutsaid first axis.

11. A heel engaging unit as defined in claim 3, wherein said second heelengaging member has a rearwardly projecting locking portion, andincluding locking means cooperating with said locking portion forreleasably maintaining said heel engaging means in a downhill runposition in which said heel engaging members are in said engagedposition and in which said heel engaging portion of said second heelengaging member is located adjacent the top surface of the ski.

12. A heel engaging unit as defined in claim 11, wherein said lockingmeans comprise a lever pivotally mounted on said elongated memberturnably between a plurality of positions, and a roller carried by saidlever and engaging in one of said positions of said lever said lockingportion for releasably maintaining said heel engaging means in saiddownhill run position.

13. A heel engaging unit as defined in claim 12, and including springmeans cooperating with said lever and being biased to yieldalblymaintain the latter in said one position thereof, said lever beingmovable against the force of said spring means to a releasing positionin which said roller is disengaged from said locking portion uponlifting of the bottom face of the heel from said second heel engagingportion and simultaneously exerting a predetermined upward pressureagainst said first heel engaging portion.

14. A heel engaging unit as defined in claim 13, wherein said springmeans are connected at one end thereof to said lever and at the otherend thereof to said one of said pair of first link means.

15. A heel engaging unit as defined in claim 13, wherein said rollercooperates with said locking portion of said second heel engaging memberin such a manner to cause, upon lifting of the heel from said secondheel engaging portion and simultaneously exerting upward pressureagainst said first heel engaging portion, first an increased stressingof said spring means, and after said locking portion engages apredetermined point of said roller, relaxing of said spring means.

16. A heel engaging unit as defined in claim 1S, wherein said springmeans is mounted and connected to said lever in such a manner thatduring movement of said lever from said one to said releasing position,the lever arm of the force component of the spring means which resiststurning of the lever to said releasing position will continuouslydecrease so that the moment necessary to turn said lever to saidreleasing position decreases while the stress of said spring meansincreases during a rst part of the turning movement of the lever fromsaid one to said releasing position.

17. A heel engaging unit as defined in claim 13 and including additionalspring means acting substantially in longitudinal direction of the skiand being arranged and constructed to assist, when said lever is in saidone position thereof, the action of said first mentioned spring means tomaintain said lever in said one position thereof.

18. A heel engaging unit as defined in claim 17 and including adjustingmeans for adjusting the force of said additional spring means.

19. A heel engaging unit as defined in claim 17, wherein said supportmeans includes a base plate adapted to be mounted on the ski, a framemounted on said base plate movable in longitudinal direction of the ski,said additional spring mean-s being connected to said base plate andsa-id frame and being biased to resist rearward movement of said framerelative to said base plate, said pair of first link means beingpivotally connected at one of the opposite ends thereof to said frame.

20. A heel engaging unit as defined in claim 19, wherein said additionalspring means includes a pair of springs aligned with each othersubstantially in longitudinal direction of the ski, and an abutmentmember located between and engaged by opposing ends of said pair ofsprings and movable in said direction, said lever engaging in said oneposition thereof said abutment member in such a manner so as to increasethe force holding said lever in said one position.

21. A heel engaging unit as defined in claim 12 and including stop meansengaging said lever in said one position thereof for determining in saidone position of the lever the position of said roller relative to saidengaging portion.

22. A heel engaging unit as defined in claim 21, wherein said stop meansincludes a screw threadingly connected to said elongated member foradjusting said one position of said lever.

23. A heel engaging unit as defined in claim 5 and includ-ing limitingmeans cooperating with said heel engaging means for limiting downwardmovement of said heel engaging means so as to maintain said heelengaging means in said walking position above said downhill runposition.

24. A heel engaging unit as defined in claim 23, wherein said limitingmeans are mounted on said lever means and engaging a part on saidsupport means during downward movement of said heel engaging means tolimit further downward movement of the latter.

25. A heel engaging unit as defined in claim 3, and including means onsaid second heel engaging portion for securing there to a memberupwardly projecting therefrom for assuring proper engagement of the heelwith said second heel engaging portion.

26. A heel engaging unit as defined in claim 3, wherein said first heelengaging member has at least one guide face for guiding a heel onto saidsecond heel engaging portion.

27. A heel engaging unit as defined in claim 3, wherein said first heelengaging member includes a first component provided with said first heelengaging portion, a second component connected to said other one of saidsecond link means, and means for adjustably connecting said first andsecond component to each other for adjusting the position of said firstand second heel engaging portions in said engaged position of said heelengaging members relative to each other.

28. A heel engaging unit as defined in claim 1, wherein said heelengaging means includes a first heel engaging member having a first heelengaging portion adapted to engage an upper face of a rim portion of theheel of a ski boot, a second heel engaging member having a second heelengaging portion adapted to be engaged by a bottom face of the heel,said first and second heel engaging members being connected to eachother movable between a step-in position in which said second heelengaging portion projects forwardly beyond said first heel engagingportion and an engaged position in which said heel engaging portions arespaced from each other a distance smaller than in said step-in position,said heel engaging portions being brought to said engaged position bypressing the bottom face of the heel against said second heel engagingportion, and guide means connected to one of said heel engaging 13members for guiding the same along a substantially circular path.

29. A heel engaging unit for a lsafety ski adapted to cooperate with afront unit of the ski for pressing a front portion of a ski boot intothe front unit of the ski binding, said heel engaging unit comprising alirst quadrangnlar guide linkage including a support member adapted tobe mounted on the ski rearwardly of the front unit thereon, a pair ofrst link means having lower ends pivotally connected spaced from eachother to said support member, and an elongated member having a rearportion to which upper ends of said pair of first link means arepi-Votally connected; heel engaging means constructed and arranged toautomatically move to a closed position gripping the heel of a ski bootwhen the user steps with the heel into the heel engaging means; a pairof second link means, one of said second pair of link means beingpivotally connected at one end thereof to one of said rst pair of linkmeans and at the other end thereof to said heel engaging means, and theother of said second pair of link means being pivotally connected at oneend thereof to said elongated member in the region of a front portion ofthe latter and at the other end thereof to said heel engaging means sothat said pair of second link means -forrrr with said heel engagingmeans a second quadrangnlar guide linkage; and releasable locking meanscooperating with said heel engaging means for yieldably maintaining thesame in said closed position and adjacent said top surface ofthe ski.

binding binding 30. A heel engaging unit as dened in claim 29, Whereinsaid one of said first link means is longer than the other of said firstlink means.

31. A heel engaging unit as dened in claim 30, wherein said heelengaging means has a locking portion, and wherein said locking meanscomprises lever means pivotally connected to said elongated member so asto be movable to and from a lock-ing position, an engaging portion onsaid lever means and engaging said locking portion of said heel engagingmeans when saidl lever means is in said locking position so as tomaintain said heel engaging means adjacent the top surface of the ski,and spring means cooperating with said lever means and biased toyieldably maintain the latter in said locking position.

References Cited yUNITED STATES PATENTS 2,758,846 8/1956 Swensen280-11.35 3,244,431 4/1966 Hatlapa 2SC-11.35 3,317,2.17 5/1967 Poiger280-11.35 3,328,044 6/1967 Klarnt 280--11.35 3,333,859 8/1967 Smolka etal 28011.35

BENJAMIN HERSH, Prim-'ary Examiner. L. DANIEL MORRIS, JR., AssistantExaminer.

